Executioner's in runes would be a nice addition to the game.

Here's my vision;

Added anti-healing and anti-shielding into the game results in;

Buffed enchanters; which results in;

Teams can't abuse stacked shields, because anti-healing and anti-shielding is added into the game from runes.

Cooldown is a bit high, it never really accounted for ultimate hunter champions or constant mid lane ganks? Cooldown reduced to 140 from 180 Initial cast no longer removes CC New effect; After 1 second your champion becomes immune to all forms of CC for 3 seconds; if you continue to be hit by forms of crowd control, the duration increases by 2 seconds up to 10.

Honestly even with this change cleanse wouldn't stack up well against ignite.. unless it removed DoT's like ignite/scorch etc.

Exhaust now slows enemies near your target; to balance it versus ignite. Now we can see more top laner's not die when they are 1v2 and under tower; Or aggressively it can slow both the enemy adc and support when your jungler ganks.